@article{1194.46014, author="Alspach, Dale E.", title="{Good $\ell_2$-subspaces of $L_p$, $p>2$.}", language="English", journal="Banach J. Math. Anal. ", volume="3", number="2", pages="49-54", year="2009", abstract="{In a recent preprint, {\it R.\,Haydon, E.\,Odell}\/ and {\it Th.\,Schlumprecht} [``Small subspaces of $L_p$,'' \url{arXiv:0711.3919}] show that a Hilbertian subspace of $L_p$, $p>2$, contains a further subspace $Z$ that is $(1+\varepsilon)$-isomorphic to $\ell_2$ and complemented in $L_p$ by a projection of norm $\le (1+\varepsilon)\gamma_p$, where $\gamma_p$ is the $L_p$-norm of a standard Gaussian random variable. Their proof uses random measures and types \`a la Krivine and Maurey. Here, the author gives another proof that avoids these means and depends only on a version of the central limit theorem for martingales.}", reviewer="{Dirk Werner (Berlin)}", keywords="{subspaces of $L_p$; well complemented subspace; Hilbertian subspace; central limit theorem}", classmath="{*46B09 (Probabilistic methods in Banach space theory) 46B25 (Classical Banach spaces in the general theory of normed spaces) 46E30 (Spaces of measurable functions) }", }